CARBON FOOTPRINT

The carbon footprint is the total amount of carbon dioxide attributable to the actions of an individual (which includes emissions through their energy use, but other unforeseen emissions as well) over a period of one year. This definition underlies the personal carbon calculations. The term owes its origins to the idea that a footprint is what has been left behind as a result of the individual's activities. Carbon footprints can either consider only direct emissions (typically from energy used in the home and in transport, including travel by cars, airplanes, rail and other public transport), or can also include indirect emissions (including CO2 emissions as a result of goods and services consumed). Bottom-up calculations sum attributable CO2 emissions from individual actions; top-down calculations take total emissions from a country (or other low-level entity) and divide these emissions among the residents (or other participants in that entity).